Self-feeding carburetor



Get, 7, 193i) E. SEIGNOL 1,777,383

SELF FEEDING GARBURE'IOR Filed July 10; 1,928 2 ShOQtS-Shfi 1 Oct. 7, 1930. SEIGNOL SELF FEEDING CAR BURETOR 2 Sheets-Sheet 2 STATS P'E'N EDOUARD SEIGNOL, '5 PARIS, FRANCE SELF-FEEDING GABBURETOR 7 Application filed July 10, 1928, Serial No. 291,591, and in France July 21, 1927.

In order that the carburation of a carburethe immediate neighbourhood. of the main tor and liquid fuel elevator should mainreservoir above the free level of the fuel in tain a practically constant value it is necesthis'lattcr a system of pipes of great length sary that the head'of fuel on the vaporizer conveying the rich carbureted mixture furshould only be subject to small negligible nished by the primary carburetor to a sec- 5 variations with respect to the total heightondary carburetor situated near the engine, of elevation of the fuel. Various devices the primary carburation device'comprising have been proposed for this purpose but they a venturi as a vaporizing device for the fuel, have certain disadvantages. and the secondary carburation device being,

10 The present invention has for its object to for example, formed of a diii'user or vcnturi 6o remedy the said disadvantage while insurin which the pipe system taking the rich ing a head on the vaporizer subject only to mixture ends, and a control member for the variations which are too small to influence, entry of air into the ditl'user under the action the carburation. of the depression which is obtained between In accordance with the present invention, the neck of the diffuser and the regulating 55 the fuel reservoir of a carburetor fuel elevavalve for the admission of carbureted mixtor is combined with a head regulator which ture, to the engine, a retarding device formed is in communication with a reservoir, the ofa second primary carburetor situated di lower end of which regulator is situated in rectly in the reservoir, and a system of tubes the immediate neighbourhood of the bottom connecting this pr nary carburetor to the 59 of the reservoir. This head reglatcr is supinduction pipe of the engine at a point situplied through its lower end in the reservoir ated below the'regulating valve. and it is in communication at its upper end The accompanying drawings represent by with the open air. The pipe by which the way of example an embodiment of the invenfuel is raised ends in the neighbourhood of tion. 75 the bottom of the head regulator. Figure 1 is a sectional elevation w1th part By this combination the head'of fuel on cutaway of a head regulating crevice on a the vaporizer is constant although the level vaporizerof a carburetor and fuel elevator of the fuel in the reservoir should be higher in accordance with the invention. than in the head regulator. It is only when Figure 2 is a sectional elevation of a syss the level of the fuel is lowered in the head tom of supply for engines in accordance with regulator through the continued lowering the invention. of the level of the fuel'in the reservoir that t Figure 3 is a fragmentary section taken a slight variation of head on the vaporizer is line 3-8 of Fig. 2. produced but if care is taken to provide the As it is illustrated in the drawing the head. maximum level in the head regulator at a re lating device for the fuel vaporizer comheight slightly above the. bottom of he respiece a head regulator 1 immersed in the ervoir, the variation of head which will refuel reservoir 2 the bottom of the head regusult will be insignificant with respect to the later 1 being placed as low as possible for normal value of this head, especially if care example in a cavity 3 stamped in the bottom is taken to make the vaporizer in the form of the reservoir 2. of a small Venturi tube, which as is known This head regulator comprises a float t possesses properties of auto-regulation as connected to a valve 5 which establishes or regards aspiration. forms the communication between the regula The invention has in addition for its obtorand the reservoir.

ject the application of the device defined The head regulator communicates with the above to a system of engine supply comprisopen air by the tube 6.

ing a main reservoir, situated at the back of The tube 7 of the fuel supply to the vaporan automobile vehicle and below the engine, izer extends practicall to the bottom of the a device of primary carburation situated in head regulator 1. it ends in its upper por- 1 tion in the figure in a chamber 8 in communication with the neck of a Venturi tube 9, 10 which raises the fuel and mi xes it with a certain quantity of air in order to form a carbureted mixture.

The action of the device is as follows If it is supposed that the level of the fuel N in the reservoir is at its maximum it is obvious that whatever this level may be it will not be lowered below N, the nrinrmal level of the fuel in the head regulator, due to the operation of the float l and of the valve 5. This head will remain absolutely constant on the vaporizer, that is to say, in this case on the venturi 9--10. It is only from the moment when the level of the fuel in the reservoir becomes lowered above the level N that the head on the vaporizer will be ditlicrent from what it was before. but the height it between the initial level N and the bottom of the reservoir is so small relatively to the height of the level N above the bottom of the reservoir as to be negligible in practice. This will especially be the case if the vaporizer is formed as a venturi as in the figure. This height It will he very small if a head regulator is adopted with a very large float the lower face of which is Very near to the bottom of the reservoir.

In Figure 2 which represents a system 0t engine supply in which the device which has just been described is applied, 1 is again the head regulator, 2 the reservoir, 4; the float, 5 the float valve, 6 the air communicating pipe, 7 the elevating tube for the fuel and 910 the vaporizing venturi. In this case, however, there has been provided a second elevation tube 7 and a second venturi 910 intended to furnish the carbureted mixture for retarded running or idling, the venturi 9-10 furnishing a very rich carbureted mixture intended for the normal running of the engine which supply is carried by a tube of considerable length 11 into the diffuser 12 of a secondary carburetor device. The tube 11 for this purpose ends in the said diffuser a little below the neck of the latter. The rich mixture for retarded running produced by the diffuser {J -10 is carried by a tube 13 to a point 14 situated down stream of the valve 15 for regulation of the quantity of carbureted mixture supplied to the engine. Air is added through the tube 16 to this rich mixture.

The secondary air intended to be mixed with the air furnished by the primary carburation device situated in the neighbourhood and above the reservoir penetrates by an entrance 17 controlled by an obturator 1S turning on an axis 19 which obturator is controlled by the vane 20 which forms a rotor piston in a chamber of the form of a sector 21 in communication by a pipe 22 with a point 23 situated between the neck of the diffuser and the throttle valve 15. A

spring, for example, aspiral spring, not illustrated, mounted on the axis 19 acts in the reverse direction to the depression which is transmitted to the chamber 1 by the pipe 22.

The action of the system is as follows In normal running the throttle 15 being opened the engine creates a depression in the diffuser. This is transmitted by the tube 11 to the primary carburation device 910 which raises through the tube 7 the fuel contained in the head regulator 1 and vaporizes it so as to form a rich carbureted mixture which is taken by suction into the diffuser. This suction transmitted by the pipe 22 to the vane 20 causes the obturator 18 to open against the action of the spring 19 and admits at each instant as a function of the variation of depression which exists in the diffuser, the quantity of air necessary in order to form, with the rich mixture conveyed by the tube 11, the carbureted mixture of optimum composition. During the whole time that the level of the fuel in the reservoir is above the normal level N of fuel in the head regulator 1, the hydrostatic head on the venturi 910 is constant which contributes to maintaining the constancy of the composition of the carbureted mixture admitted to the engine. The variation in height it between the level N and the bottom of the reservoir is small enough to have practically no influence on the delivery of fuel by the-venturi 910.

For slow running the throttle 15 is closed and it is then that the venturi 910" acts in combination with the tube 7 and the air passing through the chanenl 16 in order to furnish the appropriate carbureted mixture. During this slow running the same conditions of regulation of the head on the valve 9"1O are realized as during normal running for the venturi 910.

lVhat I claim is 1. Means for supplying fuel at a substantially constant hydrostatic head, to an internal. combustion engine, from a main reservoir situated below the engine, comprising constant-level chamber situated within the lower part of the main reservoir, said constant-level chamber being provided with an opening at the bottom thereof within the main reservoir and in close proximityto the bottom of the main reservoir, a constant-level float regulated valve for said opening, a free air vent leading from the upper part of the constantlevel chamber to the outside air, and an engine liquid fuel supply pipe leading directly from substantially the bottom of the constant-level chamber out through the main reservoir, said pipe being arranged to have its lower end submerged in and sealed by the liquid in said constant-level chamber during normal operation, together with a Venturi tube situated in the immediate neighborhood of the main reservoir above the upper level of the fuel in the main reservoir, said venturi being arranged to be fed with liquid fuel from said supply pipe and adapted to produce a mixture of air and fuel for the engine.

2. Means for supplying fuel as claimed in claim 1 in which the main tank is provided with an opening to allow the constant-level chamber to pass, with a plug arranged to close the opening, said Venturi tube being mounted upon the plug outside the main reservoir and said constant-level chamber being suspended from said plug within the reservoir.

3. Means for supplying fuel at a substantially constant hydrostatic head, to an internal combustion engine, from a main reservoir situated below the engine, comprising a constant-level chamber situated within the lower part of the main reservoir, said constant-level chamber being provided with an opening at the bottom thereof within the main reservoir and in close proximity to the bottom of the main. reservoir, a constant-level float regulated valve for said opening, a free air vent leading from the upper part of the constant-level chamber to the outside air, and an engine liquid fuel supply pipe leading directly from substantially the bottom of the constantlevel chamber out through the main reservoir said pipe being arranged to have its lower end submerged in and sealed by the liquid in said constant-level chamber during normal operation, together with a Venturi tube situated in the immediate neighborhood of the main reservoirabove the upper level of the fuel in the main reservoir, said venturi being arran ed to be fed with liquid fuel from said supply pipe and adapted to produce a mixture of air and fuel for the engine, and a secondary carburetor Venturi tube adapted to supply a further quantity of air, and a rich mixture tube arranged to convey the relatively rich mixture from the first mentioned Venturi tube to the said secondary carburetor venturi.

4. Means for supplying fuel as claimed in claim 3 having a throttle valve in the secondary Venturi tube situated up stream of the restriction in said tube, an idling liquid fuel supply pipe extending from near the bottom of the constant-level chamber out through the main reservoir, an idling Venturi tube situated similarly to said first mentioned Venturi tube and arranged to be fed with liquid from said idling liquid fuel supply pipe and aroduce a mixture of air and fuel, and an idling mixture tube arranged to convey the mixture produced by said idling Venturi tube to a point within the secondary Venturi tube down stream of the throttle valve.

5. Means for supplying fuel at a substantially constant hydrostatic head to an internal combustion engine from a main reservoir situated below the engine, comprising a constant-level chamber situated within the lower part of the main reservoir, said constant-level chamber being provided with an opening at the bottom thereof within the main reservoir and in close proximity to the bottom of the main reservoir, a float controlled valve for said opening, a free air vent leading from the upper part of said constant-level chamber to the outside air, an engine liquid fuel supply pipe leading directly from substantially the bottom of the constant-level chamber out through the main reservoir, said pipe being arranged to have its lower end submerged in and sealed by the liquid in said constant-level chamber, a primary Venturi tube mounted outside the main reservoir above the upper level of the fuel in said main reservoir, said primary Venturi tube being arranged to be fed with liquid fuel from said supply pipe and to produce a mixture of air and fuel, a secondary carburetor Venturi tube arranged to be supplied with the mixture of air and fuel produced by said primary Venturi tube and to supply additional air thereto, and means responsive to the suction in the secondary Venturi tube for controlling the amount of additional air.

In testimony whereof I have affixed my signature.

EDOUARD SEIGNOL. 

